Tremor: first-line tests

Laboratory tests

• TSH
• Plasma glucoseif needednon-French guidelineMetabolic tremor: the initial tests can look for hypoglycaemia, hyponatraemia, hypocalcaemia, hypomagnesaemia, hyperparathyroidism ^[1]. Plasma glucose and liver function tests are among the tests for enhanced physiological tremor ^[1].
• Serum electrolytesif needednon-French guidelineMetabolic tremor: the initial tests can look for hypoglycaemia, hyponatraemia, hypocalcaemia, hypomagnesaemia, hyperparathyroidism ^[1]. Plasma glucose and liver function tests are among the tests for enhanced physiological tremor ^[1].
• Serum calciumif needednon-French guidelineMetabolic tremor: the initial tests can look for hypoglycaemia, hyponatraemia, hypocalcaemia, hypomagnesaemia, hyperparathyroidism ^[1]. Plasma glucose and liver function tests are among the tests for enhanced physiological tremor ^[1].
• Serum magnesiumif needednon-French guidelineMetabolic tremor: the initial tests can look for hypoglycaemia, hyponatraemia, hypocalcaemia, hypomagnesaemia, hyperparathyroidism ^[1]. Plasma glucose and liver function tests are among the tests for enhanced physiological tremor ^[1].
• Serum creatinine with eGFR (if isolated bilateral tremor)if needednon-French guidelineA diagnostic approach proposed by Dutch neurologists (2020) includes renal function in the baseline laboratory tests for tremor, especially bilateral and isolated: renal failure is among the organ failures that cause tremor and myoclonus, and its treatment makes them disappear ^[2]. The authors specify that the yield of these tests is unknown ^[2].
• ASTif needednon-French guidelineLiver function tests are among the tests for enhanced physiological tremor, and hepatic encephalopathy among the metabolic causes to look for ^[1].
• ALTif needednon-French guidelineLiver function tests are among the tests for enhanced physiological tremor, and hepatic encephalopathy among the metabolic causes to look for ^[1].
• GGTif needednon-French guidelineLiver function tests are among the tests for enhanced physiological tremor, and hepatic encephalopathy among the metabolic causes to look for ^[1].
• Vitamin B12 (if neuropathy, deficiency possible)if needednon-French guidelineVitamin B12 deficiency is among the metabolic causes of tremor to look for ^[1]. See the “Vitamin B12 deficiency” page.
• Serum protein electrophoresis (if associated neuropathy)if needednon-French guidelineThe same Dutch neurologists (2020) have acquired causes looked for, including a paraprotein (gammopathy), when tremor is associated with neuropathy ^[2]. See the “Peripheral neuropathy” page.
• Serum lithium or valproic acid (if on treatment and overdose suspected)if neededLithium and valproic acid can cause or worsen tremor ^[1]; an antiepileptic level is measured on clinical grounds ^[3]. See the “Treatment: lithium” page.

Laboratory tests

• Caeruloplasmin
• AST
• ALT

24-hour urine collection

• 24-hour urinary copper